Such aspirations would be a tad overreaching, if expressed as the aspirations of "Canada" per se. Few enough were the Canadian aspirations, at this point in history, which envisioned a Canadian nation stretching from Nova Scotia to British Columbia. And these, for the most part, as aspirations on the behalf of Britain's lands, rather than aspirations on behalf of a Canadian union which did not yet exist. No, more so, the Alaska purchase must be regarded as a wake-up call to those who aspired towards a transcontinental claim for British North America, whose best expression would be the Canadian union. The Canadas had after all been at war with the United States, within living memory, at this point. And the Canadian union was the effect, at any rate. See this text, for a good summary of the issue.

Thanks for the reply! In 1867 Canada's western border was Ontario and BC only joined in 1871, but did they have any fear regarding having another eventual border (and invasion route) with the USA assuming the transcontinental claim for british north america worked out?

Yes, this was part of the impetus for the purchase of Rupert's Land and the joining to Confederation of British Columbia, as while the border was technically settled it was extremely fluid especially on the prairies. The wish to assert Canadian sovereignty in these areas was also the reason for the formation of the units that would in time become the famous Mounties, the Royal Canadian Mounted Police.